How much longer can the good life last?

Four years ago, the United Nations commissioned a global report to provide reliable and usable information on the relationship between ecosystems and human well-being. The assessment was broken down into 30 smaller sub-global chunks.

One of these was the Southern African Millennium Ecosystem Assessment (SAfMA). All the world’s millennium ecosystem assessment reports will be launched in March 2005.

The SAfMA report focuses on the current health of Southern Africa’s ecosystems and the implications for human well-being now and in the future. All people are absolutely dependent on ecosystem services. This is more obvious to people who live ‘close to nature” — mostly those in rural communities. It is often ignored by urban populations who are usually one or more steps removed from the actual source of the food they eat or the water they drink.

This apparent disconnection creates great risks of inappropriate policies and actions, especially because urban people are more powerful, politically and economically, than rural people.

But failure to pay attention to ecosystem services will severely limit the continent’s human development potential.

The assessment defines ecosystem services in terms of physical products, such as food, timber and water, and services like soil fertility, climate regulation and cultural values. Underpinning most ecosystem services is the biological diversity that allows ecosystems to work reliably and efficiently.

The Southern African report comes at a time of extraordinary transformation on the continent. Africa as a whole has set itself human development goals through NEPAD and the UN Millennium Goals. These aim, by 2015, to halve the number of those who face extreme poverty and hunger; to reduce child mortality because of unclean water and inadequate sanitation; to achieve universal primary education; to improve the lot of women; and to reverse the incidence of HIV/Aids, malaria and other diseases. The SAfMA report shows how likely it is that these goals will be achieved in Southern Africa.

Also, the subcontinent is in the process of transforming itself from a mainly rural population base directly involved in resource extraction and farming, and governed by traditional rules, to one that is increasingly urbanised and literate. Politics and economies are in flux. The population in Southern Africa is the fastest-growing in the world, yet growth rates are declining steadily because of the HIV/Aids pandemic and an increased use of contraceptives. And the spectre with the potential to create even more destructive change hangs over it all — climate change. All of these affect ecosystem health, and therefore our own.

The scientists involved in the report, recruited from the CSIR in South Africa and various academic institutions around the subcontinent, have been careful not to be needlessly alarmist. They did not research from scratch, but rather brought together existing information and synthesised it in an easy-to-understand way.

It is what they call a ‘multi-scale” assessment, looking at the big picture as well as the smaller realities nested within it. For example, taken over a subcontinental scale, the supply of woodfuel exceeds the demand. But there are regions that suffer desperately from a great shortage of it, where trees are being cut down faster than they can grow.

There are some areas of high concern, where three or more urgent problems converge to impact on ecosystems and human livelihoods to a dangerously high degree. Two of them are in South Africa, one in Zimbabwe, one in Malawi and one straddles the Great Lakes region.

Because most of the movement of material in ecosystems is controlled by the flow of water, the scientists found it convenient to define catchments as the unit of study. SAfMA focuses specifically on the river basins of the Gariep and the Zambezi, as well as several smaller ecosystems, like the Gorongosa-Marromeu wetlands, the Lesotho Highlands and the Richtersveld.

Encouragingly, they found that although ecosystem services in Southern Africa are declining, these are not yet in an irrecoverable state, although they face severe and growing threats.

The scientists found it striking how closely the loss of ecosystem services was associated with the loss of human freedom, well-being and life.

It was a dynamic that worked in both directions. Declining ecosystem services, in some instances, lead to competition for resources and conflict. In other places, erosion of freedoms and the rise of conflict lead to the breakdown of institutions that regulate the use of ecosystems, and the result is degradation.

Ecosystems and the services they provide are constantly changing, often in ways that we cannot anticipate. Because of this, the authors have gone to considerable lengths to explain to non-scientific decision-makers who read the report what makes ecosystems tick, how vicious spirals occur and what stability and sustainability really are. Trade-offs will inevitably have to be made, but these carry consequences.

To help decision-makers, the scientists sketched two different future scenarios.

In the African Patchwork scenario, current trends are extrapolated. While democracy and good governance take hold in some countries in Southern Africa, severely limited state effectiveness, economic mismanagement and conflict in most countries prevent the region from improving the well-being of its citizens. Regional food security does not improve, and the expansion of agricultural land together with a lack of environmental regulation and enforcement holds negative implications for biodiversity, biomass fuel, freshwater and air quality. Nature-based tourism survives under protected, high-cost conditions.

The African Partnership scenario is based on the successful adoption and implementation of current political initiatives, such as NEPAD, that aim to significantly improve governance and security, and consequently economic growth, development and human well-being in the region. Food security improves, and nature-based tourism greatly expands. Increased populations and industrial and agricultural development initially impact negatively on biodiversity, freshwater, biomass fuel and air quality, but then stabilise as effective institutions develop to regulate resource use.

The assessment focuses on freshwater resources, food and food security, livestock, woodfuel and biodiversity as well as less tangible services, including cultural, recreational, spiritual and aesthetic. It also looks at key issues, such as climate change, desertification, the link of HIV/Aids with increased food insecurity, and the conservation of biological diversity.

FRESH WATER

A defining characteristic of Southern Africa is that all the major river systems are shared. The Zambezi is shared between eight countries, the Congo and Gariep between four each, and the Okavango between three.

Four of the most developed countries in the region - Botswana, Namibia, South Africa and Zimbabwe - are also the most water-stressed.

Southern Africa has some of the highest evaporation rates — relative to rainfall — in the world.

The use of fertilisers on farms has inadvertently provided the nutrients that fuel frequent cholera outbreaks in the polluted rivers of South Africa’s KwaZulu-Natal province.

Fresh water is unevenly distributed within and across the countries of Southern Africa. The region divides roughly along the line of the Zambezi and the Cunene rivers into the water-abundant north and the water-scarce south (with some exceptions, such as the wet Lesotho highlands and the dry eastern parts of Kenya and Tanzania).

In the Zambezi River Basin, where fish is a major source of protein for low-income families, habitat degradation and pollution of fresh water ecosystems impact on fish stocks, with important implications for food security.

WOODFUEL

Southern Africa has been predicted to be on the edge of a woodfuel crisis for decades. Averaged over the entire region, though, much more wood is grown than is consumed as fuel.

But there are several worrying areas where woodfuel use is unsustainable. These include western Kenya; southeast Uganda, Rwanda and Burundi; southern Malawi; the area around Harare in Zimbabwe; the areas around Ndola and Lusaka in Zambia; Lesotho; and various parts of South Africa, notably the former homelands.

About a third of the energy used in Southern Africa as a whole is derived from trees — either as wood in rural areas, or charcoal in urban areas.

Four-fifths of the population in Southern Africa uses biomass energy for cooking and heating.

Even in coal-rich South Africa, biomass energy accounts for about 12% of total energy consumption, and despite strenuous efforts to electrify informal settlements and rural areas, about half the population still uses wood as a domestic energy source.

FOOD AND NUTRITION

Sub-Saharan Africa is considered the most food-insecure region of the world, and has the highest prevalence of malnutrition (FAO 2002). The situation is made worse by the high incidence of HIV/Aids.

The region as a whole, though, has the agricultural potential (in terms of climate, soil and terrain slope limitations) to produce enough cereal to satisfy its projected kilocalorie requirements up to 2020, taking into account climate change and population growth.

Without major interventions, however, tens of millions more people will be insecure in 2020 than now, and the Millennium Development Goals (to halve hunger in the region by 2015) will not be met.

In general, there is a high reliance in Southern Africa on purchases to meet food requirements. In South Africa, for example, access to food is mainly a function of total household income, rather than own production.

Seventy percent of South Africa is thought to be affected by soil erosion, which reduces agricultural capacity.

Africa south of the equator is chronically undersupplied with protein and the situation is steadily worsening. The recommended daily intake of protein is 52 grams. South of the Zambezi, the average is 75 grams a day and stable. North of this line it is 42 grams a day and declining.

The reasons for protein shortage north of the Zambezi River include a dependence on root crops, not cereal foods, and over-exploited freshwater fisheries. All Africa’s lakes - the source of 36% of the region’s fish - show classical signs of over-fishing.

About three quarters of the recorded dietary protein in the region is derived from vegetable sources. Around 15% comes from beef, poultry, fish and small stock, with important additional contributions from milk products and eggs. Fish is more important north of the Zambezi, while beef is more important in the drier southern countries.

Rural people on the subcontinent obtain about a third of their nutritional requirements from wild foods, such as fruits, ‘bushmeat” and insects. This proportion rises in times of stress, for example, when crops fail or income is scarce. The natural system is a food security safety net.

Vitamin A, iron and iodine are the three most critical mineral deficiencies in the region — due to narrowing diets from rural poverty, the depletion of natural fruits and vegetables, or because of poor soil.

Bushmeat increasingly constitutes a major informal industry critical to livleihoods in Southern Africa, but lack of effectivr policies means this resource is being depleted.

BIODIVERSITY

Regional biodiversity is in good condition, with more than 80% of the region in a natural or semi-natural state under no or very light use intensities.

But there is a discernible increase in threats from across the region. Alien invasives, overgrazing and over-harvesting have already made a large impact on the region’s biodiversity, eco-system services and human well being, and these are likely to spread in the absence of interventions.

Sustainably used land (for example, grazed within stocking norms, or selectively logged using low-impact methods) shows almost the same level of biodiversity as protected areas. But degradation in the form of overgrazing or clear felling on average reduces species populations by up to 60%.

On the regional scale, nature based tourism (by both Southern African residents and foreigners, but largely by urban dwellers) already contributes 9% of the SADC country economies overall, and is growing several times faster than the traditional ecosystem based extractive sectors, such as forestry, agriculture and fisheries.

One of the more positive influences on regional biodiversity trends has been made by the privatisation of conservation. A combination of private game farming, trophy hunting and nature-based tourism has expanded the conservation estate to a remarkable degree.

The biggest recent additional positive influence in the region has been the establishment of transbound.